User Contributed Notes 19 notes

Note - MySQLi doesn't support persistent connection. If you need it, you must implement it by self. This case is not covered in this note.

First - change all occurences of MYSQL_ to MYSQLI_ and mysql_ to mysqli_

Most of changes is required because mysqli* functions has no implicit link argument, so it need to be added explicitly if not present already. Even if it is present, most mysqli_ functions require 'link' argument as first (and mandatory) argument instead of last (and optional) as required by mysql_ functions. So, we need to change order of arguments at least.

So, you need to found names of all mysql_ functions used in your code, check if it need reoder of parameters or add the link parameter. Only *_connect() functions need review, but most scripts contain only few connect call.

If you use functions deprecated in mysql, then may not be impemented in mysqli. Those need to be reimplemented if required. In most case, it's very simple. In advance, PHP script written by carefull programer should not contain deprecated calls, so it's not problem in most cases at all.

Most of scripts I ported from mysql_ to mysqli_ can be converted by simple sed script followed by *_connect() function call review only. Especially when when programmer doesn't used the link as implicit argument and doesn't use deprecated functions the conversion of PHP source is trivial task and converted script work with no problem.

Special handling of some functions:

mysql_connect(),mysql_pconnect()-----------------------------------------Call with 3 or less parameters need not to be modified.4-parameters call - delete 4th parameter as mysqli is always non-persistent5-parameters - replace it by sequence of mysqli_init();mysqli_options();mysqli_real_connect()

mysql_create_db(), mysql_drop_db(), mysql_list_dbs(), mysql_db_name(),mysql_list_fields(), mysql_list_processes(), mysql_list_tables(), mysql_db_query(),mysql_table_name()------------------------------------------mysqli variant doesn't exist (those functions has been deprecated even in mysql_) but it's easy to reimplement each of it. Use apropropriate SQL command followed by standard loop for processing query results where applicable. If no connection to server yet you need to use explicit mysqli_connect call.

mysql_result()-----------------mysqli variant doesn't exist. Use one of mysqli_fetch_* variant (depending of type of mysql_result() third argument)

As soon as you get more than 250 requests per second (ever been slashdotted?) there will not be any more free TCP ports for talking to the database server, because each TCP port will be kept in TIME_WAIT for two minutes and there are only 30000 ports in the local range.

And that's not the only problem. There's also more than twice the packet rate on the network link to the database. Frankly I'd like my CPUs to spend their cycles on something producive. :-/

It should be noticed that mysqli does not support persistentconnections, so do not bother about implementing themunless you got a million hits an hour on your website.

also about using both mysql and mysqli, i want to note that under windows the best approach is to load either mysql or mysqli at runtime not both.

i know that under php5 this is deprecated but it seems to work fine. i used the same appoach under debian-linuxand seems to work aswell. just don't know for the speed cost. maybe someone can benchmark this out.

I was running into some random issues using the myqli extension with MySQL 5 on Mac OS X.

I discovered that when I compiled php 5 with the --with-mysqli flag, it was building php with the pre-installed MySQL 4 client libraries.

Heres how it fixed it to build php with the correct MySQL client libraries.

----------------I had installed the binary version of MySQL 5 from MySQL AB. It installs everything in the default location /usr/local/mysql, which is fine. The MySQL version that comes with OS X ( v.4.x, depends on your OS X version ) installs the mysql_config help utility at /usr/bin/mysql_config. When php configs, it uses that one by default, inheritently using the wrong MySQL client libs.

No problem I thought, I just changed the --with-mysqli flag to --with-mysqli=/usr/local/mysql/bin/mysql_config ( or sudo find / -name mysql_config to find yours ). Nope, php throws a build error because it can't find the matching libraries. Hmmm...

So i tested /usr/local/mysql/bin/mysql_config --version, and I am shown my most current MySQL install. The problem is that the binary editions for OS X DO NOT include the shared libs ( libmysqlclient.dylib ). Oh no, I did not want to compile MySQL myself, not because I don't know how, but because MySQL AB does not recommend it, and for good reasons. Trust me, I've found out the hard way.

So what do you do? Download the source version of MySQL 5 that matches my binary version.

Configure MySQL:

./configure --enable-shared ( it's listed as ON as default, but I want to be sure )

Build MySQL:

make ( requires Developer Tools, but you knew that )

DO NOT make install !!! I repeat, DO NOT make install unless you really wish to overwrite your binary verions, which is not a good idea. ( You can configure MySQL with the --without-server flag, but I want to be certain I don't mess up )

Ok, almost done. Go to the lib directory in your MySQL build location and go to the invisible directory, .libs . There you will find your shared libraries, namely libmysqlclient.15.0.0.dylib.

Copy this to your /usr/local/mysql/lib directory. Now do the following from the lib directory:

Now you can build your php with the correct library. After you build, check your phpinfo(); to validate the client version under the mysqli section. When I restarted Apache, it originally couldn't find my libraries, thus the /usr/local/mysql/lib/mysql directory.

John Coggeshall wrote a PHP5 ext/mysqli compatibility script for applications that still use the old ext/mysql functions. This prevents the hassle of trying to have both the mysql and mysqli extensions loaded in PHP5, which can be tricky.

If you are having trouble compiling PHP5 with MySQLi support on Linux and getting a message:"configure: error: wrong mysql library version or lib not found" and the config.log shows an error about -lnss_files being not found, here is the solution:

edit your mysql_config file and *REMOVE* all "-lnss_files" AND "-lnss_dns" entries from it.After that PHP should not complain anymore.

I successed to install php support for a mysql 4.1.7 database after several attempts because the instructions are not clear.I have a server with linux SuSe 9 enterprise with apache 1.3.31. I installed mysql from rpm files, i installed php 4.3.9 as dynamic library. this version database needs its own client library else the mysql functions in php will not work.configuration must be as following:

If you want to build php with both the Mysql and mysqli extensions, make sure your mysql distribution comes with shared libraries or build mysql yourself with shared libraries. With only static mysql libraries the compile process will fail.

I tryed Marco Kaiser's way of getting both mysql_* and mysqli_*, but it failed for me. However I could get it working this way: First of all I installed the MySQL 4.1.3 binary disribution acourding to the manual. Then I simply passed these ./configure arguments:

I had a problem compiling PHP 5.2.5 with mysqli enabled on Mac OS X. Whether this problem was unique to me I do not no, so I am posting this for anybody else that runs into the same problem. Configure would run right to the end, but I had it telling me something had failed and that it was likely messed up. Upon checking debug.log I noticed this:

" if you want to use both the old mysql and the new mysqli interface, load the Makefile into your editor and search for the line beginning with EXTRA_LIBS; it includes -lmysqlclient twice; remove the second instance"

then you can:

makemake install

......Please note: the mysql-dev must be installed or you won't have a mysql_config anywhere. I installed the mysql-dev rpm

Further note: the information about the Makefile's duplicate instances of "-libmysqlclient" came from Michael Kofler. Thanks should be directed to him. He gives more details at the following link: